Method of refining lead.



tempted the lead would not cover the entire lit) "a? TE TA Fm,

PHILLIP WERNER, OF PI IILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE -HALF '10 RUSSELL SPICER, 01Ev WILLMAR, MINNESOTA.

METHOD or nnrmme LEAD.

No Drawing.

To all whom it may concern:

Be it known that I, PHILLIP WERNER, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented newf and useful Improvements in Methods of Refining Lead, of which the following is a specification.

This invention relates generally to the treatment of metals, and more particularly to the treatment of lead and to the coating of steel or iron with the treated lead, the immediate improvement having to do with the preparation of the lead preliminary to the coating operation.

Variousattempts have been made to coat one metal with another metal having a lower melting point, and particularly to coat iron or steel with pure lead, but the products produced so far as ll can determine have always been ofa rather imperfect nature, and especiall in the case of lead, as the lead would fail to properly adhere to the steel or' iron and would tend to peel ofi. Furthermore, in the processes heretofore atsurface of, the material, but small spaces termed pin holes would develop which would allow moisture to come into contact with the iron or steel plate and cause it to oxidize or rust at such exposed places.

To overcome the difficulties attendant on the use of pure lead as a coating material, alloys of lead with some other element, such as tin have been resorted to, but due to the fact that tin is somewhat expensive, and to the further fact that it admits corrosion of the iron or steel, plates covered @ipectfiwflcn of Letters Patent.

Application filed January 3, 1917. Serial No. 140,342.

Patented new, re, rate,

which all in holes, and the like, are entirely eliminated The above and other objects are obtained by treating the plates of steel or iron to be coated with a suitable fiux, and then dipping them into a molten mass of lead treated in accordance with my invention; which contemplates preliminary preparation with a ping the iron plates into the lead, the plates are immersed in a flux preferably containmg muriatic-acld, salamoniac and zinc. In-

stead of dipping the plate into a flux of muriatic acid, salamoniac and zinc, this flux may be stirred into the molten lead when it will quickly rise to the top of the bathand form a molten layer, through which molten layer, the articles pass when the same are dipped into the bath, so that the articles will take up part of the flux to bring them to the proper condition to cause the lead to adhere to the plate. Another suitable flux for use on top of the molten lead may be made by placing salamoniac and zinc chlorid upon the surface of the lead, when they melt together and form a fluid layer, to which small portions of muriatic acid may be added from time to time if desired The lead is prepared by taking commercially pure lead, such as is ordinarily bou h on the market, introducing it into any suitable pot or vat, heating the same and maintaining it at a temperature above its melt-- ing point, preferably, about 900 or 1000 Fahn, at which temperature a suitable resinous material is introduced and held below the surface of the lead byany convenient method, such as a wire basket, or pair of tongs, etc.; the resinous material being thereupon destructively distilled by the action of the hot lead, and the lead subjected to the. action of the products of such destructive distillation. The products of such destructive distillation will rise within the lead and thoroughly permeate the molten mass.

As examples of suitable resinous substances, I have found that amber, common rosin and dry pine wood containing pitch, such as pine knots, are adapted to perform and do perform this process of purification, but it is to be understood that various other resinous substances may be used, and this invention is not limited to the resinous substances above enumerated.

The products of the destructive distilla tion of resinous substances are reducing and acidic in their nature, and it is thought that their effect is to reduce or combinewith the oxids of leadand other metals present in the molten lead, and thus remove said oxids. I have reason to believe that said oxids are the cause of the difliculties heretofore experienced in obtaining an adherent coat of lead on iron or steel articles.

Amber, common rosin, and dry pine wood containing pitch,'such as pine knots, when destructively distilled yield products of a reducing and acidic nature which produce the desired effect. I have further found that by using a. resinous substance containing succinic acid, or the like, very advantageous results are obtained. As an example of a resin containing an organic acid preferably succinic, I mention amber.

The attainment of the proper degree of purification is easily determined by immersing suitably cleaned pieces of iron or steel, as above described, and observing the character of the coating obtained. When the lead has once been properly purified, and

freed from oxid, it remains in this condition as long as it is protected from air andother ox1d1z1ng influences, and is ready for use 1n coating iron or steel by means of any of the well-known devices used in coating similar articles with zinc, or by-other suitable devices for introducing and removing the articles tobe coated.

In order to further facilitate the removal of the oxid of iron or the oxid of any other metal which may be present, and to prevent their reformation, I find it advisable to protect the surface of the molten lead from the action of the oxygen of the air either by means of a. layer of charcoal, or a layer of some suitable salt or salts, such as the flux above described. The flux forms a layer, which during the treatment of the lead, prevents the oxygen of the an from COl'IllIlg into contact with the lead. It is found that,

when treating the lead to the products of destructive distillation of a resinous subunderstood that while I have set forth certain fluxes to be used for cleaning the iron or steel to be coated, these are examples only, and any other suitable flux "may be used, as this invention is not limited in any Way to the cleansing of the plates in any particular manner prior to the coating thereof.

My invention makes it possible to coat iron or steel articles with lead on a commercial scale as easily as they are now coated with zinc and obtain a smooth and adherent coat of lead. While I have particularly mentioned and used lead, this same method of purification is adapted and suitable for the treatment of other ductile metals for removing their dissolved oxids and permitting their adhesion to other metals.

I claim:

1. The process of refining a metal which consists in reducing the metal to a molten state, treating the molten metal with the products of the destructive distillation of a resinous substance or substances, and protecting the surface of the metal from contact with the atmosphere.

2. The process of refining lead which consists in reducing the lead to a molten mass, maintaining a layer upon the surface of the lead to prevent contact between the lead and atmosphere, and treating it with the products of the destructive distillation of a resinous substance or substances.

3. The process of refining lead consisting in reducing it to a molten condition, maintaining a (layer of material upon the surface of the lead to prevent contact between the lead and atmosphere, and immersing therein a resinous substance or substances.

4. The process of refining lead which consists in reducin the lead to a molten mass, maintaining a ayer of material upon the surface of the lead to prevent contact between the lead and atmosphere, and treating the molten mass with a resinous substance or substances which when destructively distilled yield products of a reducing and acidic and acidic nature, permitting the products 0 of destructive distillation to permeate the molten mass, and maintaining a layer of material on the surface of the ductile metal to 1 prevent contact with the atmosphere.

10 layer of material upon the surface of the lead to prevent contact between the lead and atmosphere.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

PHILLIP RNER.

Witnesses:

S. F. T. MARTIN, I. V. TRATTNER. 

